This invention relates to a swing, and more particularly to an improved drive system for moving the swing in a back and forth manner.
A swing generally consists of a stationary support frame to which a swinging frame is pivotally mounted. A seat or chair is mounted to the swinging frame, and is suspended by the swinging frame from the stationary support frame. To swing the seat or chair, it is known to provide a swinging drive arrangement to move the swinging frame in a back and forth manner. With mechanical drives as are known in the prior art, however, the swinging action is somewhat jerky when the swing reaches its forwardmost or rearwardmost swinging positions, during transition of the swinging frame movement from one direction to another. This characteristic is undesirable in that the occupant of the seat or chair is subjected to the jerkiness imparted to the swinging frame, resulting in the occupant's swinging experience being less than satisfactory.
Automated swings of the type described above are commonly used by parents to swing an infant. In addition, another market for automated swings of this type is elderly people, who are generally known to enjoy the back and forth movement offered by a rocking chair or a gliding chair.
It is an object of the present invention to provide an automated swing with an improved swing drive arrangement, for use with any type of swing in which a swinging frame is mounted for pivoting movement to a support frame. It is a further object of the invention to provide a swing drive arrangement which imparts a smooth and even swinging motion to the swinging frame, to eliminate jerkiness involved in transition of the swinging frame from movement in one direction to movement in the other direction. It is yet another object of the invention to provide such a swing drive arrangement which is simple in its construction and operation, yet which is highly satisfactory in imparting swinging motion to the swinging frame.
In accordance with the invention, a drive arrangement is interposed between the support frame and the swinging frame of an automated swing for pivoting the swinging frame relative to the support frame. The drive arrangement includes a resilient member engageable with the swinging frame assembly, and a reciprocable mechanism acting on the resilient member for intermittently tensioning the resilient member to engage the swinging frame assembly to pull it in a first direction, and releasing tension on the resilient member to allow the swinging frame assembly to return in a second direction. The resilient member may be a drive belt constructed of a resilient material. A rotatable element is provided on the swinging frame, and the drive belt is trained about the rotatable element. The rotatable element may take the form of a bearing member engageable with a shaft mounted to the swinging frame. The shaft is mounted off-center of the swinging frame. The reciprocable mechanism may take the form of a rotatable drive shaft, a rotary power source for imparting rotation to the drive shaft, and an eccentric drive member mounted to the drive shaft and engageable with the drive belt. The eccentric drive member is preferably an elliptical member mounted to the drive shaft, with the drive shaft extending through the elliptical member and being mounted thereto such that the center of the drive shaft is coincident with the major axis of the elliptical member. With this arrangement, rotation of the drive shaft results in the elliptical member intermittently tensioning the drive belt and releasing tension on the drive belt. When the drive belt is tensioned, it stretches while pulling the swinging frame in one direction. When tension on the drive belt is relieved, the weight of the swinging frame, the seat or chair, and its occupant results in movement of the swinging frame assembly in the opposite direction. Subsequent re-tensioning of the drive belt upon further rotation of the elliptical member again pulls the swinging frame assembly in the first direction, until tension on the belt is once again relieved after further rotation of the drive shaft and the elliptical member. Continued rotation of the drive shaft results in a repeated back and forth swinging motion being imparted to the swinging frame, and thereby to the seat or chair and its occupant.
In a particularly preferred form of the invention, the swinging frame comprises frame members located one on either side of the seat or chair. A drive belt and an elliptical drive member are located one adjacent each of the pair of frame members.
The invention further contemplates a method of pivoting the swinging frame relative to the support frame to swing the chair, substantially in accordance with the foregoing summary.
Various other objects, features and advantages of the invention will be made apparent from the following description taken together with the drawings.